Coolant temp sensor, please help - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 05-21-2012, 05:03 PM   #1
Elite Member
Thread Starter
iTrader: (13)
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 5,702
Total Cats: 237
Default Coolant temp sensor, please help

Hey guys, just trying to get my car together.. i broke the coolant temp sensor on the front waterneck while working on my car, and i needed a new one. So i bought
http://www.amazon.com/OEM-9305-Coolant-Temperature-Sensor/dp/B000CSOI9E/ref=au_pf_pfg_s?ie=UTF8&Model=Miata|1110&n=15684181&s=automotive&Make=Mazda|80&Year=1990|1990&vehicleType=automotive&newCar=1&carId=001 http://www.amazon.com/OEM-9305-Coolant-Temperature-Sensor/dp/B000CSOI9E/ref=au_pf_pfg_s?ie=UTF8&Model=Miata|1110&n=15684181&s=automotive&Make=Mazda|80&Year=1990|1990&vehicleType=automotive&newCar=1&carId=001

Anyways, its incorrect. This thing has 2 prongs, the one on my car has 1. It says its for a 1.6l mazda miata, etc. I cross referenced this a few times before buying it. WTF did i buy? And can I make it work?

Here is just the picture for reference :
Attached Thumbnails
Coolant temp sensor, please help-2157cht8k7l._sl500_aa300_.jpg  
Fireindc is offline   Reply With Quote
Old 05-21-2012, 05:06 PM   #2
Elite Member
Thread Starter
iTrader: (13)
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 5,702
Total Cats: 237
Default

I also just pulled it up on Vatozones website.. same thing it seems: http://www.autozone.com/autozone/par...25898_0_18589_

Fireindc is offline   Reply With Quote
Old 05-21-2012, 05:09 PM   #3
Elite Member
Thread Starter
iTrader: (13)
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 5,702
Total Cats: 237
Default

FML. Sorry for this waste of a thread. I do believe i found what i need..

http://www.autozone.com/autozone/par...uestid=1306399



Dandy.. now i get to wait another week to drive my car.. ;(

I'm an idiot. For future reference to any n00bs(like myself obviously), the temp sensor on the waterneck on the FRONT of the engine is just a SWITCH for the fan.
Fireindc is offline   Reply With Quote
Old 05-21-2012, 06:21 PM   #4
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,915
Default

There are a total of -=> THREE <=- CLT sensors on a 1.6l Miata. The two-pin one goes at the back of the head and feeds the ECU. Next to it is a single-pin sensor which feeds the dash gauge. Then at the front, on the thermostat housing, is another single-pin sensor, although that one is technically a thermoswitch, not a temp sensor, and it controls the radiator fan.

The one in the link is correct for this application.
Joe Perez is offline   Reply With Quote
Old 05-21-2012, 06:44 PM   #5
Elite Member
Thread Starter
iTrader: (13)
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 5,702
Total Cats: 237
Default

I <3 you Joe. And your fancy shirts.
Fireindc is offline   Reply With Quote
Old 05-21-2012, 08:17 PM   #6
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,915
Default

For future reference:

The '94-'97 cars have two sensors, both at the back of the head. It's essentially identical to the setup on the '90-'93, except that the thermoswitch on the thermostat housing goes away, and the radiator fan is controlled by the ECU instead.

The '99-'05 cars are kind of interesting. Physically, they have only one CLT sensor, again located at the back of the head inside the heater-core outlet fitting. However, this sensor has three pins instead of one or two. Internally, this sensor actually contains two elements, which are electrically equivalent to the two sensors on a '94-'97 engine combined into one housing. One of the sensor elements uses two wires on the connector and drives the ECU, the other element uses a single wire (and the case for ground) and drives the temp gauge in the dashboard.

This is one of the annoying little problems with transplanting a '99+ engine into an earlier car- you have to find a new hole to plug the "other" sensor into. Fortunately, most Miata owners are accustomed to exploring new holes.
Joe Perez is offline   Reply With Quote
Old 05-22-2012, 02:16 AM   #7
Elite Member
Thread Starter
iTrader: (13)
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 5,702
Total Cats: 237
Default

Quote:
Originally Posted by Joe Perez View Post
Fortunately, most Miata owners are accustomed to exploring new holes.


That is "fortunate". bahaha.
Fireindc is offline   Reply With Quote
Old 05-22-2012, 05:11 AM   #8
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,107
Total Cats: 518
Default

For future reference it doesn't keep you from driving your car, it only keeps you from driving your car at idle for long periods of time. A safety pin can be put in the diagnostics box to turn the fans on full time too, if you'd prefer to error on the side of safety. Forget which pins though. I wanna say GND and TAB, but I could be terribly wrong.
curly is offline   Reply With Quote
Old 05-22-2012, 12:13 PM   #9
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,915
Default

Quote:
Originally Posted by curly View Post
Forget which pins though. I wanna say GND and TAB, but I could be terribly wrong.
GND to TFA. TAB sounds the horn.
Joe Perez is offline   Reply With Quote
Old 05-22-2012, 12:29 PM   #10
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,865
Total Cats: 1,790
Default

ground TAB. it's fun. your neighbors will love you.
Braineack is offline   Reply With Quote
Old 05-22-2012, 02:08 PM   #11
Elite Member
Thread Starter
iTrader: (13)
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 5,702
Total Cats: 237
Default

You are sure some helpful ----------ers.

Which is why i've been on this forum.. for 6 years now? HOLY ----.
Fireindc is offline   Reply With Quote
Old 05-22-2012, 05:10 PM   #12
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,107
Total Cats: 518
Default

Arg, I was going to say TAB or TFA.

I've completely rewired my fans outside of the Mazda harness, or I would have tested it for you.
curly is offline   Reply With Quote
Old 05-22-2012, 05:42 PM   #13
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,865
Total Cats: 1,790
Default

TAB is horn
TFA is fan.
Braineack is offline   Reply With Quote
Old 06-14-2014, 12:56 AM   #14
Newb
 
Join Date: Jun 2014
Posts: 6
Total Cats: -1
Default

I am actually having the same problem... I was accelerating and all of a sudden my rpms dropped to nothing and my car just shut down, I looked under the hood and saw I broke the engine coolant fan switch and bought the one on the auto zone link you posted with one prong!

(Duralast/Cooling Fan Switch - Radiator (TU146) | AutoZone.com)

I installed the switch and my car still wont start... I'm not sure what it is. I heard spark plugs, camshaft position sensor, fuel injectors, fuel pump regulators and other stuff. I also am not getting an RPM signal... Any ideas?
bmkpriest is offline   Reply With Quote
Old 06-14-2014, 01:07 AM   #15
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,107
Total Cats: 518
Default

That switch you replaced is for the fans. Literally, all it does is ground the wire going to it at a set temperature to turn the fans on. Has ZERO to do with running the car.

Start by checking your timing, the belt could have snapped. If that's good, ground all the spark plugs on the valve cover and crank the car to see if you've got spark.
curly is offline   Reply With Quote
Old 06-14-2014, 02:06 PM   #16
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,865
Total Cats: 1,790
Default

What curly said.

that switch is nothing to do with what happened.


you need to confirm: RPMS, fuel, spark, air.

first check would be if the cams are turning, then go from there. Each thing could have a multitude of possible reasons.


but it sounds like your timing belt broke. open the oil fill cap, shine in a flash light and look at the cams, then have someone crank it. I bet they dont move.
Braineack is offline   Reply With Quote
Old 10-26-2015, 02:19 PM   #17
Newb
 
Join Date: Aug 2015
Posts: 3
Total Cats: 0
Default

Hey guys, I know it's been a while since any one has posted here and I am torn between posting in the MS threads but its a question about the coolant sensor.

I am planning on running my ms2 (non pnp ms2e???) in parallel for fuel only, I know braineack and everyone says it's stupid but I have never tuned a car so I am slowly learning.

My main question is this: Can I cut the wire that goes to the ecu for the coolant temp sensor (leaving the switch and dash sensor to do their own thing) without having any spark timing change? I know the coolant temp messes with the A/F ratio but if I am running fuel through the MS then I would assume it wouldn't be a problem but I'm the newb so I should be asking questions.

I know the ms will need iat (have a separate gm open element), O2 (wideband?), and coolant, and I don't know what to do about the coolant sensor so any input would be appreciated.
zaderej is offline   Reply With Quote
Old 10-26-2015, 05:02 PM   #18
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,915
Default

Quote:
Originally Posted by zaderej View Post
I am planning on running my ms2 (non pnp ms2e???) in parallel for fuel only, I know braineack and everyone says it's stupid but I have never tuned a car so I am slowly learning.
It's stupid, and is going to cause you more headaches than it saves.

That having been said, I'll answer your question:


Quote:
Originally Posted by zaderej View Post
My main question is this: Can I cut the wire that goes to the ecu for the coolant temp sensor (leaving the switch and dash sensor to do their own thing) without having any spark timing change? I know the coolant temp messes with the A/F ratio but if I am running fuel through the MS then I would assume it wouldn't be a problem but I'm the newb so I should be asking questions.

If you disconnect the two-wire CLT sensor from the ECU, you will break a lot of things. Spark advance and idle speed control come to mind immediately, I suspect there are others as well. This is in addition to setting off the MIL.


Presupposing that you really need to share, the correct method is to splice into the CLT line and feed it into the MS in parallel with the stock ECU. This will require removing the pullup resistor from the CLT line internal to the MS, and recalibrating the MS to accommodate the value of the stock pullup resistor in the OEM ECU. This value varies by year, and notes on doing it this way are in this thread: https://www.miataturbo.net/useful-sa...76/#post177420

Last edited by Joe Perez; 10-26-2015 at 08:58 PM.
Joe Perez is offline   Reply With Quote
Old 10-26-2015, 08:53 PM   #19
Newb
 
Join Date: Aug 2015
Posts: 3
Total Cats: 0
Default

Thank you Joe, I wasn't sure what else the ecu used coolant temp for but that makes sense.

I know everyone says parallel sucks but I am afraid of ******* my pcb or car up because I don't know what circuits to use because everyone has a different method and no one has the same set up on their car so I have a lot of research to do with a lot of broken links...

The the things I am confused about are:
What to do with the fuel pump
What circuit to use for ignition (I would like to follow How to MegaSquirt your Mazda Miata but they say they use the VR circuit which confused me. Or could use your circuit that brings me to my other confusion which is how to wire the thing.

I know I have quite a bit of research to do but it doesn't help when the main page says its old and outdated, too many links are broken and no one has one way of doing it.
zaderej is offline   Reply With Quote
Old 10-26-2015, 09:03 PM   #20
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,915
Default

(I can't believe I'm comtinuing to give advice on this topic...)


Quote:
Originally Posted by zaderej View Post
I know everyone says parallel sucks but I am afraid of ******* my pcb or car up because I don't know what circuits to use because everyone has a different method and no one has the same set up on their car so I have a lot of research to do with a lot of broken links...
It's not that it sucks, it's that it's harder. The wiring is more complex, the tuning is more complex, and there are a lot of gotchas.


(What year is your car, anyway? This matters a lot when talking about ECU setup.)




Quote:
Originally Posted by zaderej View Post
The the things I am confused about are:
What to do with the fuel pump
What circuit to use for ignition (I would like to follow How to MegaSquirt your Mazda Miata but they say they use the VR circuit which confused me. Or could use your circuit that brings me to my other confusion which is how to wire the thing.
Since your post above indicated that you were only interested in driving the fuel injectors, neither the fuel pump nor the ignition circuit are of interest.




Quote:
Originally Posted by zaderej View Post
I know I have quite a bit of research to do but it doesn't help when the main page says its old and outdated, too many links are broken and no one has one way of doing it.
The pages are outdated and the links are dead because nobody has actively updated any information on this subject in many years, mostly because we realized there's an easier way to do it.

Have you considered just buying an MSPNP?
Joe Perez is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
MSPNPPro-MM0105: Coolant Temperature Output slomiata MEGAsquirt 5 10-07-2015 02:11 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:21 AM.